Oversized pipe detention

[swowens]

I am working on design of a site that needs storm water detention without an above ground pond, so I am going with oversized pipes. Does anyone know how to calculate incremental volume of a sloped pipe? I can't seem to find info in any of the literature.
Thanks

 

[cvg]

thread194-101642

this has been discussed on the above thread

 

[swowens]

Thanks for your help, this is exactly what I was looking for.